There exists much literature relating to collision avoidance and warning systems for land vehicles. Examples of such literature include the following references, the disclosures of which are hereby incorporated by reference:
Merrill I. Skolnik, Introduction to Radar Systems, 1981, 2nd Edition, Chapter 3.3, FM-CW Radars.
Daniels, D. J. Radar for Hazard Warning, 18th International Symposium on Automotive Technologies, May 30-Jun. 3, 1988.
Radar Handbook, Merrill I. Skolnik, McGraw-Hill Book Company, 1970, particularly chapters 21 and 25, pertaining to tracking radar and ground echo;
Eli Brookner, Raytheon Company, Wayenad, Mass., U.S.A. Radar Technology, 1977, particularly chapters 9 and 26 on Fast Fourier Transforms and Kalman filters;
Chandler, R. A. and Wood, Lockett E., System considerations for the design of radar beaching sensor, IEEE Trans. on Vehicular Technology, Vol. VT - 26, No. 2, May 1977;
Erwin F. Belohoubek, Radar Control for Automotive Collision Mitigation and Headway Spacing, IEEE Trans. on Vehicular Tech., Vol. VT-31, No. 2, May, 1982; and
Nagy, Louis L. Electromagnetic Reflectivity Characteristics of Road Surfaces, IEEE Trans. on Vehicular Tech. Vol. VT-23, No. 4, Nov. 1974.
Existing collision warning systems have not yet attained acceptance in the marketplace, due in part to their high false alarm rates, which causes them to become a nuisance to the driver.